[Federal Register Volume 64, Number 97 (Thursday, May 20, 1999)]
[Rules and Regulations]
[Pages 27472-27476]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-12173]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Parts 17 and 87

[WT Docket No. 96-211, FCC 99-40]


Use of 112-118 MHz for Differential Global Positioning System 
(GPS) Correction Data and the Use of Hand-Held Transmitters on 
Frequencies in the Aeronautical Enroute Service

AGENCY: Federal Communications Commission.

ACTION: Final rule.

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SUMMARY: This Report and Order (R&O) amends the Commission's rules 
regarding the use of 112-118 MHz for differential Global Positioning 
System (GPS) correction data, the use of hand-held transmitters on 
frequencies in the Aeronautical Enroute Service, and to update Part 17 
of our rules to incorporate by reference two recently revised FAA 
Advisory Circulars. These amendments were adopted in response to 
petitions for rule making filed by the Federal Aviation Administration 
and the Aeronautical Radio, Inc. The effect of these amendments would 
increase aircraft and airport safety and facilitate the efficient use 
of aeronautical radio spectrum.

DATES: These regulations are effective May 20, 1999. The incorporation 
by reference of certain publications listed in the regulations is 
approved by the Director of Federal Register May 20, 1999.

FOR FURTHER INFORMATION CONTACT: James Shaffer of the Commission's 
Wireless Telecommunications Bureau at (202) 418-0680 or via email at 
[email protected].

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's R&O, 
FCC 99-40, adopted February 25, 1999, and released March 3, 1999. The 
full text of this Report and Order is available for inspection and 
copying during normal business hours in the FCC Reference Center, Room 
246, 1919 M Street N.W. Washington, D.C. The complete text may be 
purchased from the Commission's copy contractor, ITS, Inc., 1231 20th 
St. N.W., Washington, D.C. 20036, telephone (202) 857-3800.

Summary of R&O

    1. This R&O amends Part 87 of our rules to permit aeronautical 
ground stations to use frequencies in the 112-118 MHz band to transmit 
differential Global Positioning System (GPS) information to aircraft 
equipped to use advanced landing systems in response to a petition for 
rule making filed by the Federal Aviation Administration (FAA). This 
R&O also allows the use of hand-held radios for direct communications 
between ground service personnel and flight crews on frequencies 
allocated to the Aeronautical Enroute Service in response to a petition 
for rule making filed by Aeronautical Radio, Inc. (ARINC). Finally, 
this R&O updates part 17 of our rules to incorporate by reference two 
recently revised FAA Advisory Circulars. The actions will increase the 
safety and efficiency of aircraft navigation and movement of aircraft 
in and around airports. Further, these amends should promote the use of 
new radio technologies beneficial to aircraft without allocating 
additional spectrum.

Administrative Matters

Final Regulatory Flexibility Analysis

    2. As required by the Regulatory Flexibility Act, 5 U.S.C. 603 
(RFA), Initial Regulatory Flexibility Analyses (IRFA) were incorporated 
in the Notice of Proposed Rule Makings WT Docket 96-1 and WT Docket 96-
211.1 The Commission sought written public comments on the 
proposals in the Unicom NPRM and Aviation Safety NPRM, including on the 
IRFA. The Commission's Final Regulatory Flexibility Analysis (FRFA) in 
this Report and Order conforms to the RFA, as amended by the Contract 
With America Advancement Act of 1996.2
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    \1\ Amendment of Part 87 of the Commission's Rules to Permit 
Automatic Operation of Aeronautical Advisory Stations (Unicoms), WT 
Docket 96-1, Notice of Proposed Rule Making, 11 FCC Rcd 1084 (1996), 
61 FR 8905, (March 6, 1996), (Unicom NPRM); Amendment of part 87 to 
Permit the Use of 112-118 MHz for Differential Global Positioning 
System (GPS) Correction Data and the Use of Hand-held Transmitters 
on Frequencies in the Aeronautical Enroute Service and Amendment of 
Part 17 Concerning Construction, Marking, and Lighting of Antenna 
Structures, WT Docket No. 96-211, Notice of Proposed Rule Making, 11 
FCC Rcd 15391 (1996), 61 FR 60673, (November 29, 1996), (Aviation 
Safety NPRM).
    \2\ Public Law No. 104-121, 110 Stat. 847 (1996) (CWAAA). Title 
II of the CWAAA is ``The Small Business Regulatory Enforcement 
Fairness Act of 1996'' (SBREFA), codified at 5 U.S.C. 601 et seq.
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I. Need for and Objective of the Proposed Rules

    3. Our objective is to improve safety in air navigation by 
increasing pilots' access to advisory information, promoting the use of 
satellite technology for the precision landing of aircraft and allowing 
ground crews to communicate with aircraft on aeronautical enroute 
frequencies, and to incorporate by reference two recently revised FAA 
Advisory Circulars. The Report and Order in this proceeding modified 
the Commission's rules to increase the safety and efficiency of 
aircraft navigation and movement of aircraft in and around airports.
    4. The public interest is served by modifying our rules to permit 
the operation of aeronautical advisory stations (unicoms) in an 
unattended, automated mode, allow aeronautical ground stations to 
transmit differential GPS augmentation data to aircraft, allow the use 
of mobile radios for direct communications between ground service 
personnel and flight crews on Aeronautical Enroute Service frequencies 
and incorporate, by reference, two FAA Advisory Circulars.

II. Summary of Significant Issues Raised by the Public Comments in 
Response to the Initial Regulatory Flexibility Analysis

    5. No comments were submitted in direct response to the IRFA. We 
have, however, reviewed general comments that may impact small 
businesses.
    6. Much of the impact will be on small businesses that use, 
manufacture, design, import, or sell equipment, and will increase 
safety and efficiency at airports by allowing new uses and technologies 
for the purpose of communicating important information for flight and 
ground safety. Commenters submitted suggestions to improve the 
technical and operational criteria of the proposals. This Report and 
Order directly benefits small businesses by providing smaller airports 
that do not have sufficient resources to staff a unicom station with an 
automated and economically viable alternative to provide important 
advisory information, providing airports with satellite technology for 
the precision landing of aircraft to facilitate approaches and landings 
in poor weather conditions, and improving the safe ground operations at 
airports and improve the provision of services and supplies to aircraft 
on the ground. These actions should increase the safety and efficiency 
of aircraft navigation and movement of aircraft in and around airports.

III. Description and Estimate of the Number of Small Entities to 
Which the Rules Apply

    7. The rules adopted in this Report and Order will affect small 
businesses that use, manufacture, design, import, sell, or use aviation 
equipment designed for an automated unicom, a GPS augmentation system 
operating in the 112-118 MHz band, and mobile radios

[[Page 27473]]

used for direct communications between ground service personnel and 
flight crews on Aeronautical Enroute Service frequencies. There are no 
Commission-imposed requirements, however, for any entity to use these 
products.

Estimates for Unicoms

    8. The unicom service provides for air-ground communications 
primarily between general aviation aircraft and airport facilities. 
Unicom transmissions are limited to the necessities of safe and 
expeditious operation of aircraft, including runway conditions, types 
of fuel available, wind conditions, weather information, dispatching, 
and other necessary safety information. Unicom transmissions may 
include, on a secondary basis, communications pertaining to the 
efficient portal-to-portal transit of an aircraft, such as available 
ground transportation, food, and lodging. Unicoms must provide 
impartial information concerning available ground services, and must 
provide service to any aircraft station upon request and without 
discrimination. For the purpose of determining whether a licensee is a 
small business as defined by the Small Business Administration (SBA), 
each licensee would need to be evaluated within its own business area.
    9. Because the Regulatory Flexibility Act amendments were not in 
effect until the record in this proceeding was closed, the Commission 
was unable to request information regarding the number of small 
entities that are unicoms. Therefore, the Commission is unable at this 
time to determine the number of small businesses which could be 
impacted by the rules. However, the Commission's data indicates that 
there were 2775 unicoms licensees operating at the end of October 1996. 
Further, because any entity engaged in providing unicom service is 
eligible to hold a unicom license, these rules could potentially impact 
every small business involved in aviation. Additionally, there are 
small businesses that will manufacture, design, import, or sell 
equipment. We concluded that these small businesses are classified in 
Communications Equipment, N.E.C., (Standard Identification Code 3669) 
as entities employing less than 750 employees as defined in 13 CFR 
121.201. The size data provided by the SBA shows that 469 firms out of 
498 firms in the Communications Equipment, N.E.C. classification have 
less than 750 employees but did not enable us to make a meaningful 
estimate of the number of potential manufacturers which are small 
businesses.3
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    \3\ U.S. Small Business Administration 1992 Economic Census 
Industry and Enterprise Report, Table 1D, SIC Code 3669, (Bureau of 
the Census data adapted by the Office of Advocacy of the U.S. Small 
Business Administration).
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Estimates for Differential GPS

    10. Differential GPS is ground reference stations licensed to 
private entities using unassigned VOR frequencies in the 112-118 MHz 
band to transmit differential GPS augmentation data to aircraft to 
improve safety in approach and landing of aircraft. For the purpose of 
determining whether a licensee is a small business as defined by the 
Small Business Administration (SBA), each licensee would need to be 
evaluated within its own business area. Additionally, there are small 
businesses that will manufacture, design, import, or sell equipment. We 
concluded that these small businesses are classified in Communications 
Equipment, N.E.C., (Standard Identification Code 3669) as entities 
employing less than 750 employees as defined in 13 CFR 121.201. We 
invited comment on whether this is the correct definition to use, but 
received no comment on this issue. The size data provided by the SBA 
shows that 469 firms out of 498 firms in the Communications Equipment, 
N.E.C. classification have less than 750 employees but did not enable 
us to make a meaningful estimate of the number of potential GPS 
manufacturers which are small businesses.4 However, based on 
information from the U.S. GPS Industry Council we estimate that this 
would include approximately 110 small businesses that would be affected 
by this proposed rule change.
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    \4\ U.S. Small Business Administration 1992 Economic Census 
Industry and Enterprise Report, Table 1D, SIC Code 3669, (Bureau of 
the Census data adapted by the Office of Advocacy of the U.S. Small 
Business Administration).
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IV. Description of Projected Reporting, Recordkeeping, and Other 
Compliance Requirements of the Rules

    11. There are several reporting, recordkeeping, and compliance 
requirements applicable to the Commission licensees and equipment 
manufacturers. These new requirements are necessary to minimize 
radiofrequency interference of the equipment, and to specify the 
responsibilities in operating unicom.
    (1) In order to facilitate operation of aviation equipment, these 
rules may have significant economic impact on a substantial number of 
small businesses. Prior to marketing aviation equipment in the U.S., a 
manufacturer must have the unit type accepted by the Commission under 
the technical criteria set forth in the Commission's Rules. In order to 
have a unit type accepted, a small entity would have to test the radio 
equipment and provide clerical support to file the requisite FCC 
application forms. Both of these functions could be handled by a third 
party. We estimate that the initial cost to the manufacturer to meet 
this requirement, if done by a third party, is $900 to test the 
equipment and complete the filing information, and would require the 
electronic engineering professional skills. Additionally, there would 
be a $425 equipment authorization fee to file the application for type 
acceptance. These costs are one time costs to type accept the equipment 
and assure that interference to other radio users is minimized.
    (2) In order to clarify the responsibilities in operating unicoms, 
we require all unicom licensees at airports having more than one unicom 
to jointly sign a letter of agreement, prior to the operation of a 
unicom in automatic mode at such an airport, stating the name(s) of the 
licensee(s) who will control the automatic unicom and, if applicable, 
how control of the automatic unicom will be divided. A copy of the 
agreement must be kept with each licensee's station authorization. We 
estimate that approximately 50 licensees will require 0.7 hours to 
prepare and file the agreement required.

V. Steps Taken by Agency To Minimize Significant Economic Impact on 
Small Entities Consistent With Stated Objectives

    12. The rules would require differential GPS transmitters to be 
type accepted in accordance with the technical criteria set forth in 
part 87 subpart D of our rules, in lieu of the more exacting 
specifications contained in RTCA Document No. DO-217. This flexible 
approach promotes technological innovations in differential GPS 
equipment so long as such equipment is compatible with the National 
Airspace System. Under our present treatment of transmitters operating 
in the 108-137 MHz band, the FAA is given a 21-day period to object to 
any application for type acceptance that would adversely affect the 
performance of the National Airspace System. The rules also take 
measures to expedite coordination procedures between applicants, the 
FAA, and the Commission concerning the assignment of a frequency and 
time slot for differential GPS ground stations. In order to reduce 
administrative burdens on both the public and the Commission,

[[Page 27474]]

we permit mobile units in the aeronautical enroute service to operate 
under the same authorization and call sign as the associated 
aeronautical enroute station. This approach would eliminate the need 
for aviation service organizations to submit forms and fees to the 
Commission. These decisions benefit small entities and give them an 
opportunity to provide recommendations to further improve the impact 
and processes.

VI. Report to Congress

    13. The Commission shall send a copy of this Final Regulatory 
Flexibility Analysis, along with the Report and Order, in a report to 
Congress pursuant to the SBREFA.5 A copy of this FRFA will 
also be published in the Federal Register.
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    \5\ See 5. U.S.C. 801(a)(1)(A).
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Ordering Clauses

    14. Accordingly, it is ordered that, pursuant to the authority of 
Sections 4(i), 303(r), 307(e), and 332(a)(2) of the Communications Act 
of 1934, as amended, 47 U.S.C. 154(i), 303(r), 307(e) and 332(a)(2), 
parts 80 and 87 of the Commission's Rules, 47 CFR Parts 17 and 87 are 
amended as set forth in the Rule Changes, effective May 20, 1999.
    15. It is further ordered that these proceedings are terminated.

List of Subjects

47 CFR Part 17

    Antenna, Aviation safety, Communications equipment, Incorporation 
by reference, Radio.

47 CFR Part 87

    Aviation safety, Communications equipment, Radio.

Federal Communications Commission.
Magalie Roman Salas,
Secretary.

Rule Changes

    For the reasons discussed in the preamble, the Federal 
Communications Commission amends 47 CFR parts 17 and 87 as follows:

PART 17--CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES

    1. The authority citation for Part 17 continues to read as follows:

    Authority: Secs. 4, 303, 48 Stat. 1066, 1082, as amended; 47 
U.S.C. 154, 303. Interpret or apply secs. 301, 309 48 Stat. 1081, 
1085 as amended, 47 U.S.C. 301, 309.

    2. Section 17.23 is revised to read as follows:


Sec. 17.23  Specifications for painting and lighting antenna 
structures.

    Unless otherwise specified by the Commission, each new or altered 
antenna structure to be registered on or after January 1, 1996, must 
conform to the FAA's painting and lighting recommendations set forth on 
the structure's FAA determination of ``no hazard,'' as referenced in 
the following FAA Advisory Circulars: AC 70/7460-1J, ``Obstruction 
Marking and Lighting,'' effective January 1, 1996, and AC 150/5345-43E, 
``Specification for Obstruction Lighting Equipment,'' dated October 19, 
1995. These documents are incorporated by reference in accordance with 
5 U.S.C. 552(a). The documents contain FAA recommendations for painting 
and lighting structures which pose a potential hazard to air 
navigation. For purposes of this part, the specifications, standards, 
and general requirements stated in these documents are mandatory. The 
Advisory Circulars listed are available for inspection at the 
Commission Headquarters in Washington, DC, or may be obtained from 
Department of Transportation, Property Use and Storage Section, 
Subsequent Distribution Office, M483.6, Ardmore East Business Center, 
3341 Q 75th Avenue, Landover, MD 20785, telephone (301) 322-4961, 
facsimile (301) 386-5394. Copies are also available for public 
inspection at the Office of the Federal Register, 800 North Capitol 
Street, Suite 700, Washington, D.C.

PART 87--AVIATION SERVICES

    3. The authority citation for Part 87 continues to read as follows:

    Authority: 48 Stat. 1066, 1082, as amended; 47 U.S.C. 154, 303, 
307(e) unless otherwise noted. Interpret or apply 48 Stat. 1064-
1068, 1081-1105, as amended, 47 U.S.C. 151-156, 301-609.

    4. Section 87.5 is amended by revising the definition of 
``automatic weather observation station'' to read as follows:


Sec. 87.5  Definitions.

* * * * *
    Automatic weather observation station (AWOS) or automatic surface 
observation station (ASOS). A land station located at an airport and 
used to automatically transmit weather information to aircraft.
* * * * *
    5. Section 87.131 is amended by adding a footnote to Aeronautical 
advisory entry and adding to the end of the table, an entry for 
Differential GPS to read as follows:


Sec. 87.131  Power and emissions.

* * * * *

----------------------------------------------------------------------------------------------------------------
                                                                  Authorized emission(s)
          Class of station            Frequency  band/frequency             \9\              Maximum power \1\
----------------------------------------------------------------------------------------------------------------
Aeronautical advisory..............  VHF........................  A3E                     10 watts.\10\
 
*                  *                  *                  *                  *                  *
                                                        *
Differential GPS...................  VHF........................  G7D                     Various.\2\
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\1\ The power is measured at the transmitter output terminals and the type of power is determined according to
  the emission designator as follows:
  (i) Mean power (pY) for amplitude modulated emissions and transmitting both sidebands using unmodulated full
  carrier.
  (ii) Peak envelope power (pX) for all emission designators other than those referred to in paragraph (i) of
  this note.
\2\ Power and antenna height are restricted to the minimum necessary to achieve the required service.
            *                *                *                *                *                *
   *
\9\ Excludes automatic link establishment.
\10\ Power is limited to 0.5 watt, but may not exceed 2 watts when station is used in an automatic unattended
  mode.

    6. Section 87.133 is amended by adding to the table in paragraph 
(a) in the (5) Band-100 to 137 MHz: entry, an entry for Differential 
GPS to read as follows:


Sec. 87.133  Frequency stability.

    (a) * * *

[[Page 27475]]



------------------------------------------------------------------------
 Frequency band (lower limit exclusive,
 upper limit inclusive), and categories    Tolerance \1\   Tolerance \2\
               of stations
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*            *            *            *            *            *
                                      *
(5) Band-100 to 137 MHz:
 
*            *            *            *            *            *
                                      *
    Differential GPS....................  ..............         2
 
*            *            *            *            *            *
                                      *
------------------------------------------------------------------------
\1\ This tolerance is the maximum permitted until January 1, 1990, for
  transmitters installed before January 2, 1985, and used at the same
  installation. Tolerance is indicated in parts in 10\6\ unless shown as
  Hertz (Hz).
\2\ This tolerance is the maximum permitted after January 1, 1985 for
  new and replacement transmitters and to all transmitters after January
  1, 1990. Tolerance is indicated in parts in 10\6\ unless shown as
  Hertz (Hz).

* * * * *
    7. Section 87.137 is amended by adding to the table in paragraph 
(a) in its alphabetical order, an entry for G7D to read as follows:


Sec. 87.137  Types of emission.

    (a) * * *

----------------------------------------------------------------------------------------------------------------
                                                                         Authorized bandwidth (kilohertz)
                                                                 -----------------------------------------------
         Class of emission               Emission designator                                         Frequency
                                                                   Below 50 MHz    Above 50 MHz      deviation
----------------------------------------------------------------------------------------------------------------
 
                 *            *            *            *            *            *            *
G7D................................  14K0G7D....................  ..............               25
 
                 *            *            *            *            *            *            *
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    8. Section 87.139 is amended by revising the introductory text in 
paragraph (a), and paragraph (j) to read as follows:


Sec. 87.139  Emission limitations.

    (a) Except for ELTs and when using single sideband (R3E, H3E, J3E), 
or frequency modulation (F9) or digital modulation (F9Y) for telemetry 
or telecommand in the frequency bands 1435-1535 MHz and 2310-2390 MHz 
or digital modulation (G7D) for differential GPS, the mean power of any 
emission must be attenuated below the mean power of the transmitter 
(pY) as follows:
* * * * *
    (j) When using G7D for differential GPS in the 112-118 MHz band, 
the amount of power during transmission under all operating conditions 
when measured over a 25 kHz bandwidth centered on either of the second 
adjacent channels shall not exceed -25 dBm and shall decrease 5 dB per 
octave until -52 dBm.
    9. Section 87.171 is amended by adding in its alphabetical order 
the symbol and class of station for DGP to read as follows:


Sec. 87.171  Class of station symbols.

* * * * *
    DGP--Differential GPS.
* * * * *
    10. Section 87.173 is amended by adding in numeric order the 
listing 112-118 MHz to read as follows:


Sec. 87.173  Frequencies.

* * * * *
    (b) * * *

----------------------------------------------------------------------------------------------------------------
     Frequency or frequency band               Subpart              Class of station             Remarks
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
112-118 MHz.........................  Q                         DGP                      Differential GPS.
 
*                  *                  *                  *                  *                  *
                                                        *
----------------------------------------------------------------------------------------------------------------

    11. Section 87.187 is amended by revising paragraph (y) 
introductory text and the introductory text of paragraph (y)(4) to read 
as follows:


Sec. 87.187  Frequencies.

* * * * *
    (y) Brief keyed RF signals (keying the transmitter by momentarily 
depressing the microphone ``push-to-talk'' button) may be transmitted 
from aircraft for the control of automated unicoms on the unicom 
frequencies listed in paragraph (y)(3) of this section, or for the 
control of airport lights on the following frequencies:
* * * * *
    (4) Aviation support station frequencies listed in Sec. 87.323(b): 
* * *
* * * * *
    12. A new Sec. 87.219 is added to Subpart G to read as follows:


Sec. 87.219  Automatic operations.

    (a) A station operator need not be present when an automated unicom 
is in operation.
    (b) Unicoms operating in an automated mode must comply with the 
requirements of paragraphs (1)-(5) of this section, in addition to the 
requirements applicable to non-automated unicom operations.
    (1) An automated unicom must transmit only in response to 
interrogating signals from aircraft,

[[Page 27476]]

including but not limited to the brief keyed RF signals specified in 
Sec. 87.187(y).
    (2) An automated unicom must monitor the unicom frequency prior to 
transmission, and provide a brief delay between the aircraft's 
interrogating signal and the automatic unicom's response.
    (3) Automated advisory transmissions must be as brief as possible, 
and must never exceed one minute in length.
    (4) An automated unicom may not provide weather information at an 
airport that has an operational, FAA-certified, automatic weather 
facility, unless the unicom itself is certified by the FAA.
    (5) If weather information is provided by an automated unicom:
    (i) weather sensors must be placed in order to adequately represent 
the weather conditions at the airport(s) to be served;
    (ii) the weather information must be proceeded by the word 
``advisory;''
    (iii) the phrase ``automated advisory'' must be included when the 
weather information was gathered by real-time sensors or within the 
last minute; and,
    (iv) the time and date of the last update must be included when the 
weather information was not gathered within the last minute.
    (c) Only one automated unicom may be operated at an uncontrolled 
airport. Prior to the operation of an automated unicom at an airport 
with more than one unicom licensee, all of the licensees at that 
airport must sign a letter of agreement stating which licensee(s) 
control the automated unicom operations, and, if control is to be 
shared among several operators, how that control will be divided or 
scheduled. The original or a copy of the letter of agreement must be 
kept with each licensees' station records. Within 90 days of the date 
upon which a new unicom operator is licensed at an airport where more 
than one unicom is authorized, and an automated unicom is being 
operated, an amended letter of agreement that includes the new 
licensee's signature must be signed or automated unicom operations must 
cease.
    13. Section 87.261 is amended by adding paragraphs (e) and (f) to 
read as follows:


Sec. 87.261  Scope of service.

* * * * *
    (e) Mobile units may be operated under an aeronautical enroute 
station authorization so long as the units are limited to use at an 
airport and are only used to communicate with aircraft on the ground or 
the associated aeronautical enroute station. Mobile units are further 
limited to operation on the VHF frequencies listed in 87.263(a)(1).
    (f) Mobile units licensed under paragraph (e) of this section shall 
not be operated on air traffic control frequencies, nor cause harmful 
interference to, communications on air traffic control frequencies.
    14. Section 87.419 is revised to read as follows:


Sec. 87.419  Supplemental eligibility.

    Only one control tower or RCO will be licensed at an airport.
    15. Section 87.475 is amended by adding paragraph (e) to read as 
follows:


Sec. 87.475  Frequencies.

* * * * *
    (e) Frequencies available for differential GPS stations. 
Frequencies in the 112-118 MHz band may be assigned to Special Category 
I (SCAT-I) ground stations for differential GPS data links.
    (1) The frequencies available are on 25 kHz centers with the lowest 
assignable frequency being centered at 112.000 MHz and the highest 
assignable frequency being centered at 117.950 MHz.
    (2) Applicants must coordinate a frequency, time slot assignment, 
and three-letter identifier with the FAA and provide this information 
to the Commission upon application.
    16. Subpart S is amended by revising the heading to read as 
follows:

Subpart S--Automatic Weather Stations (AWOS/ASOS)

    17. Section 87.525 is revised to read as follows:


Sec. 87.525  Scope of service.

    Automatic weather observation stations (AWOS) and automatic surface 
observation stations (ASOS) must provide up-to-date weather information 
including the time of the latest weather sequence, altimeter setting, 
wind speed and direction, dew point, temperature, visibility and other 
pertinent data needed at airports having neither a full-time control 
tower nor a full-time FAA Flight Service Station. When a licensee has 
entered into an agreement with the FAA, an AWOS or an ASOS may also 
operate as an automatic terminal information station (ATIS) during the 
control tower's operating hours.
    18. Section 87.527 is amended by revising paragraphs (b) and (c) to 
read as follows:


Sec. 87.527  Supplemental eligibility.

* * * * *
    (b) Eligibility for an AWOS, an ASOS, or an ATIS is limited to the 
owner or operator of an airport or to a person who has entered into a 
written agreement with the owner or operator for exclusive rights to 
operate and maintain the station. Where applicable a copy of the 
agreement between the applicant and owner or operator of the airport 
must be submitted with an application.
    (c) Only one AWOS, ASOS, or ATIS will be licensed at an airport.
    19. Section 87.529 is amended by revising the fourth and fifth 
sentences to read as follows:


Sec. 87.529  Frequencies.

    * * * Normally, frequencies available for air traffic control 
operations set forth in subpart E will be assigned to an AWOS, ASOS, or 
to an ATIS. When a licensee has entered into an agreement with the FAA 
to operate the same station as both an AWOS and as an ATIS, or as an 
ASOS and an ATIS, the same frequency will be used in both modes of 
operation.

[FR Doc. 99-12173 Filed 5-19-99; 8:45 am]
BILLING CODE 6712-01-P